1. Field of the Invention
This invention relates to a method of fabricating an improved cold electrode or cathode for use with a laser. The invention cold electrode is of particular use in ring laser gyro applications that require the use of a cold or unheated cathode.
2. Description of the Prior Art
Ring laser gyroscopes typically use an unheated or cold aluminum cathode on the ring laser gyro body as a source of electron emission for laser operation. Ring laser gyro bodies are commonly manufactured from materials having a very low coefficient of thermal expansion to achieve positional stability between optical elements such as mirrors. The life of the gyro is influenced by several factors including the emission stability of the active surface within the electrode or cathode and the life of the seal established between the cold electrode and the gyro body. Electrodes or cathodes made of aluminum have very high thermal coefficients of expansion in relation to the thermal coefficient of expansion of the ring laser gyro body material. Thermal cycling of the gyro and the cathode results in thermal cycling of the mechanical seal between the cathode and the gyro body. A large difference between the thermal expansion of the cathode and the thermal expansion of the gyro body produces a large strain on the cathode seal with each thermal cycle. A large strain on the gyro seal, coupled with a large number of thermal cycles, contributes to a shortened gyro life.